Direction finding (DF) is the process of obtaining the direction of arrival bearings of radio-frequency (RF) emitters of interest. Geolocation (GEO) is the process of determining the locations of RF emitters of interest based on DF estimates. DF and GEO are commonly utilized to identify, track and geolocate various sources of RF transmissions.
DF and GEO techniques for identifying and locating RE emitters are usually based on energy/amplitude comparison, interferometric, time-of-arrival (TOA), time-difference-of-arrival (TDOA) and other antenna null-steering approaches. These approaches typically require special antennas, close-tolerance amplitude/phase RF receiver components, enhanced receiver dynamic range and expanded processing bandwidth.
In general, a DF/GEO system collects RF signals from a source RF emitter by using an array of spatially displaced antennas. Nearly all DF algorithms require that signals received by the antennas are routed to multiple signal processors synchronously. These signal processors are then utilized to compare the amplitude/energy, phase and TOA/TDOA from the received signals in order to derive the location of the source RE emitter.
The combination of various DF and GEO techniques forms the basis of many complex DF systems. The present disclosure provides a method for improving GEO and GEO accuracy in a DF system.